DESCRIPTION (adapted from the application) Many differentiated cell types are derived from populations of relatively undifferentiated stem cells which retain capacity for continued proliferation and self-renewal. Stem cell populations are maintained by a crucial balance between alternate cell fates: daughter cells must choose between stem cell identity and self-renewal capacity vs. commitment to differentiate after a limited number of amplification divisions. Alteration of this crucial balance can lead to stem cell tumors or loss of tissue renewing capacity. During embryogenesis, stem cells are the principal units of organogenesis and tissue formation. Stem cells retained in adulthood are the units of regeneration, for example hematopoietic stem cells in bone marrow transplantation. Despite their biological and medical importance, the molecular mechanisms that specify stem cell fate and regulate self-renewal vs. differentiation are poorly understood. Recently developed functional assays allow isolation of several stem cell types. At the same time, work in genetically manipulatable model systems has begun to identify both cell intrinsic and extrinsic molecular mechanisms that specify asymmetric stem cell-like divisions leading to daughter cells with different fates. The goal of this meeting is to bring together scientists working on stem cells with scientists probing the genetic control of asymmetric cell division and cell fate to discuss the mechanisms that might control stem cell specification, self-renewal and commitment to differentiation. The topics presented and discussed at this meeting will inform students and postdoctoral fellows across disciplinary lines and give them a strong foundation from which to undertake the fundamental research required to realize the potential benefits in tissue regeneration and disease treatment promised by recent advances in stem cell research.